Amino acids are the basic components of proteins in both food for human consumption and animal feed. Amino acids are classified as either "essential" or "non-essential." The amino acid composition of proteins is varied and distinct for each protein. Proteins having a vegetable or microbial origin usually lack an ideal balance of the essential amino acids required by higher forms of animal life including humans. In order to correct for any deficiencies in the amino acid content of vegetable proteins, proteins of animal origin are often fed in conjunction with vegetable proteins. Attempts have also been made to correct any amino acid deficiency by supplementing both human food and animal feed with the specific amino acids that are limiting.
Supplementing livestock and poultry feeds with amino acids is a well-established and widely accepted practice. For example, lysine monohydrochloride, dl-methionine and methionine hydroxy analog are amino acid supplements used in large volume in the feed industry.
It is also well established to supplement animal feed with amino acids complexed with a variety of metals, including calcium and various transition metals, including copper, zinc and iron. The purpose of these metal-amino acid complexes is to supply dietary requirements of both metal ions and essential amino acids to the animal. However, so that the metal-amino acid complexes can be provided in an effective bioavailable form, the complexes are described in the art as water-soluble, which allows the metal and/or amino acid to be readily absorbed after ingestion.
A series of patents assigned to Zinpro Corporation relates to water-soluble "complex salts" of transition metals and alpha amino acids, in particular for use as feed additives and animal nutrition. For example, U.S. Pat. No. 4,021,569, issued to M. Abdel-Monem on May 3, 1977 relates to 1:1 zinc methionine complex salts. The patent describes the complex salts as containing a coordination bond formed between the zinc and the alpha-amino group, in addition to an electrostatic attraction bond between the zinc and the carboxylic acid group. The 1:1 complex salts of zinc and methionine are reported to be of great importance in ensuring absorption of the zinc and methionine and their subsequent distribution and effective utilization in animals. Because the 1:1 complex salts are water-soluble, the zinc and methionine are disclosed as being readily utilized after ingestion.
Other Zinpro patents relating to water soluble complexes of metal ions and amino acids include U.S. Pat. Nos. 4,948,594, 4,900,561, 4039,681, 4,067,994, 4,764,633 and 5,278,329.
U.S. Pat. No. 5,278,329 teaches that the complexes which are the subject matter of the above listed Zinpro patents are characterized as 1:1 complex salts because 1:1 complex salts are more water-soluble, more biovailable and more efficiently converted to provide the maximum effective body usage of both the transition metal and the amino acid.
While the processes of fermentation and digestion which take place in the rumen of ruminant animals largely benefit the animals under natural feeding conditions, modern husbandry requires that, for optimum production of meats and/or milk, ruminant animals should be fed a proportion of their dietary requirements in the form of nutrients which will not undergo any alteration or degradation in the rumen. It also is necessary, however, that such nutrients not interfere with the normal processes of rumen fermentation.
Proteins used in ruminant feeds are largely of vegetable origin and thus may be supplemented with sources of non-protein nitrogen to help support the growth of microorganisms in the rumen. The primary source of protein for post-ruminal digestion and absorption is rumen microbial protein. In the case of protein metabolism, however, it is known that at certain periods during the growth, development and lactation of cows, insufficient microbial protein is produced in the rumen to meet the animal's full requirements for maximum growth or maximum milk production. It is therefore desirable that a proportion of the protein requirement of cows be met by supplying a supplement containing protein or individual essential amino acids which are not degraded in the rumen. This can improve feed conversion efficiency, growth rate and production as compared with using an equal weight of degradable protein or amino acid.
There have been a number of methods proposed for protecting fats and proteins from the effects of rumen fermentation so that they are not digested until they reach the abomasum or intestine of the ruminant. These methods have for the most part depended upon protecting such fats and/or proteins (and sometimes other nutritional materials such as minerals or essential vitamins) via a coating which resists the fermentation processes of the rumen.
There exists a need for being able to feed to a ruminant animal essential amino acids in a form in which the degradative effects of the normal fermentation and digestion processes in the rumen can be minimized or avoided. More specifically, a need exists for a form of amino acid that can bypass normal fermentation and digestion processes of the rumen and reach the abomasum or intestine of the ruminant in a form in which the animal can take the fullest advantage of the nutritive value of the amino acid.
Although amino acids are available from pharmacies, health food stores and supermarkets, their value as food supplements for humans is uncertain in most cases. The most widely used amino-acid-based supplement is monosodium glutamate, which functions as a flavor enhancer.
The sale of pasta products world-wide occupies a very large volume market. In the United States and many other countries, these products contain a very high percentage of processed semolina wheat. During the course of preparing this ingredient, the quality of the protein is degraded, thus causing a deficiency in the lysine content of the protein. Furthermore, the manner in which pasta is prepared for consumption, namely boiling in water, largely precludes any value of supplementing pasta products with lysine because the lysine can easily leach out of the pasta during boiling. Thus, there also exists a need for an additive for food products for human consumption, specifically pasta, containing one or more essential amino acids in a form such that when the additive is combined with a food product, the amino acid remains in the food product after boiling or other means of cooking.
One objective of the present invention is therefore to provide a process for preparing a water-insoluble, calcium or magnesium salt of an alpha amino acid.
Another important objective of the present invention is to provide a feed supplement for ruminant animals comprising a water-insoluble salt of an alpha amino acid, which is able after ingestion to bypass the normal fermentation and digestion processes which occur in the rumen of a ruminant animal.
A further objective of the present invention is to provide an enriched food product for human consumption which contains a water-insoluble salt of an alpha amino acid which allows the food product to maintain substantially all of the amino acid during and after normal manufacturing and cooking processes.
The method of accomplishing these and other objectives will become apparent in the following description of the invention.